Climbing organisms are constantly challenged to make their way rapidly and reliably across varied and often novel terrain.
A diversity of morphologically and mechanically disparate attachment strategies have evolved across widely distributed phylogenetic
groups to aid legged animals in scaling these surfaces, notable among them some very impressive adhesive pads. Despite the
differences between, for example, the dry fibrillar pads of geckos and the smooth, secretion-aided pads of stick insects,
I hypothesize that they face similar functional demands in their environment. I outline three broad criteria defining dynamic
biological adhesion: reusability, reversibility, and substrate tolerance. Organismal adhesive pads must be able to attach
repeatedly without significant decline in performance, detach easily at will, and adhere strongly to the broadest possible
range of surfaces in their habitat. A survey of the literature suggests that evidence for these general principles can be
found in existing research, but that many gaps remain to be filled. By taking a comparative, integrative approach to biological
dynamic adhesion, rather than focusing on a few model organisms, investigators will continue to discover new and interesting
attachment strategies in natural systems.
Keywords Adhesion - Biomimetics - Fibrillar adhesives - Wet adhesives - Locomotion
Communicated by I. D. Hume.